Medical and laboratory gloves often must be donned rapidly when used to perform time-sensitive medical procedures or laboratory experiments. Therefore, an important characteristic of these elastomeric articles is ease of putting the articles on the wearer's hand, or donnability. Additionally, articles such as medical gloves or condoms, for example, are anticipated to be worn by the user for extended periods of time. Because certain elastomeric articles are used with relatively higher frequency as well as with prolonged duration, important characteristics of such articles include their physical properties and their comfort of use.
A variety of medical gloves, e.g., surgical gloves and examination gloves, are well known and readily available in the medical field. The chemical and physical properties of elastomers used in such gloves have been researched, and gloves exhibiting desirable properties in accordance with their usage have been developed. Properties such as tensile strength and elongation modulus, as well as coatings and lubricants, which enhance their usage and/or donning characteristics, have been investigated. A variety of elastomeric polymer compositions have been examined as well, including formulations using natural and synthetic latex.
The manufacturing process for producing elastomeric articles from natural or synthetic rubber latex involves a curing step during which crosslinking or vulcanization through sulfur groups occurs between the polymer units. Conventional processes for making elastomeric articles from natural or synthetic latex typically involve preparing a latex dispersion or emulsion, dipping a former in the shape of the article to be manufactured into the latex and curing the latex while on the former. Desirable properties of certain elastomeric articles such as tensile strength are substantially affected by the cross-linking and curing stages of the manufacturing process.
Coating the inner surface of a glove is well-known in the art. U.S. Pat. No. 3,813,695 to Podell teaches coating a hydrophilic hydrogel plastic on the inner surface of a glove. U.S. Pat. No. 4,143,109 to Stockum discloses coating the inner surface of a glove with a layer comprising an elastomeric material having particulate matter randomly distributed throughout, the particulate matter having a size greater than the thickness of the elastomeric layer so that the particles protrude from the surface. In addition, U.S. Pat. No. 4,499,154 to James and U.S. Pat. No. 4,575,476 to Podell teach coating a hydrogel polymer to a rubber article to improve the dry skin lubricity where the hydrogel polymer is a copolymer of 2-hydroxyethylmethacrylate with methacrylic acid (MAA) or with 2-ethylhexyl acrylate (EHA) or with both MAA and EHA. U.S. Pat. No. 5,088,125 to Ansell discloses coating the hand contacting surface of a glove with an elastomeric material comprising a blend of an ionic polyurethane and a second particulate polymer having particle size greater than that of the ionic polyurethane which results in the surface having a cluster of particles on it. U.S. Pat. No. 5,284,607 to Chen teaches coating an elastomer surface with an antiblocking composition with particles distributed throughout, the majority of the particles having a size greater than the thickness of the antiblocking composition layer so that the particles form protrusions on the surface. U.S. Pat. Nos. 5,405,666 and 5,395,666 to Brindle teach coating an elastomeric article with a dry slip conferring coating which comprises a binder (a polymer with specific properties) and substantially nonaggregated microparticles (silica) of about 4 to about 20 micrometers such that the microparticles are enveloped by the binder but are partially protruding therefrom thus imparting to the surface a microroughened appearance. Finally, U.S. Pat. Nos. 6,391,409 and 6,673,404 to Yeh teach coating a natural rubber or synthetic elastomer glove on the skin-contacting surface with a cross-linked nitrile rubber blended with a silicone. Interposed between the nitrile rubber coating and the elastomeric glove is an intermediate layer of a rubber blend comprised of natural or synthetic rubber and nitrile rubber.
There exists a need in the medical device field for elastomeric articles, especially gloves, with improved donnability while maintaining the desirable properties found in the natural rubber counterpart, including a comfortable feel.